1HTML::Mason::CGIHandlerU(s3e)r Contributed Perl DocumentaHtTiMoLn::Mason::CGIHandler(3)
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6 HTML::Mason::CGIHandler - Use Mason in a CGI environment
7
9 In httpd.conf or .htaccess:
10 <LocationMatch "\.html$">
12 Action html-mason /cgi-bin/mason_handler.cgi
13 AddHandler html-mason .html
14 </LocationMatch>
15 <LocationMatch "^/cgi-bin/">
16 RemoveHandler .html
17 </LocationMatch>
18 <FilesMatch "(autohandler|dhandler)$">
19 Order allow,deny
20 Deny from all
21 </FilesMatch>
22 A script at /cgi-bin/mason_handler.pl :
24 #!/usr/bin/perl
26 use HTML::Mason::CGIHandler;
27 my $h = HTML::Mason::CGIHandler->new
29 (
30 data_dir => '/home/jethro/code/mason_data',
31 allow_globals => [qw(%session $u)],
32 );
33 $h->handle_request;
35 A .html component somewhere in the web server's document root:
37 <%args>
39 $mood => 'satisfied'
40 </%args>
41 % $r->err_header_out(Location => "http://blahblahblah.com/moodring/$mood.html");
42 ...
43
45 This module lets you execute Mason components in a CGI environment. It
46 lets you keep your top-level components in the web server's document
47 root, using regular component syntax and without worrying about the
48 particular details of invoking Mason on each request.
49 If you want to use Mason components from within a regular CGI script
51 (or any other Perl program, for that matter), then you don't need this
52 module. You can simply follow the directions in the Using Mason from a
53 standalone script section of the administrator's manual.
54 This module also provides an $r request object for use inside
56 components, similar to the Apache request object under
57 "HTML::Mason::ApacheHandler", but limited in functionality. Please
58 note that we aim to replicate the "mod_perl" functionality as closely
59 as possible - if you find differences, do not depend on them to stay
60 different. We may fix them in a future release. Also, if you need
61 some missing functionality in $r, let us know, we might be able to
62 provide it.
63 Finally, this module alters the "HTML::Mason::Request" object $m to
65 provide direct access to the CGI query, should such access be
66 necessary.
67 "HTML::Mason::CGIHandler" Methods
69 · new()
70 Creates a new handler. Accepts any parameter that the Interpreter
72 accepts.
73 If no "comp_root" parameter is passed to "new()", the component
75 root will be $ENV{DOCUMENT_ROOT}.
76 · handle_request()
78 Handles the current request, reading input from $ENV{QUERY_STRING}
80 or "STDIN" and sending headers and component output to "STDOUT".
81 This method doesn't accept any parameters. The initial component
82 will be the one specified in $ENV{PATH_INFO}.
83 · handle_comp()
85 Like "handle_request()", but the first (only) parameter is a
87 component path or component object. This is useful within a
88 traditional CGI environment, in which you're essentially using
89 Mason as a templating language but not an application server.
90 "handle_component()" will create a CGI query object, parse the
92 query parameters, and send the HTTP header and component output to
93 STDOUT. If you want to handle those parts yourself, see the Using
94 Mason from a standalone script section of the administrator's
95 manual.
96 · handle_cgi_object()
98 Also like "handle_request()", but this method takes only a CGI
100 object as its parameter. This can be quite useful if you want to
101 use this module with CGI::Fast.
102 The component path will be the value of the CGI object's
104 "path_info()" method.
105 · request_args()
107 Given an "HTML::Mason::FakeApache" object, this method is expected
109 to return a hash containing the arguments to be passed to the
110 component. It is a separate method in order to make it easily
111 overrideable in a subclass.
112 · interp()
114 Returns the Mason Interpreter associated with this handler. The
116 Interpreter lasts for the entire lifetime of the handler.
117 $r Methods
119 · headers_in()
120 This works much like the "Apache" method of the same name. In an
122 array context, it will return a %hash of response headers. In a
123 scalar context, it will return a reference to the case-insensitive
124 hash blessed into the "HTML::Mason::FakeTable" class. The values
125 initially populated in this hash are extracted from the CGI
126 environment variables as best as possible. The pattern is to merely
127 reverse the conversion from HTTP headers to CGI variables as
128 documented here:
129 <http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html#6.1>.
130 · header_in()
132 This works much like the "Apache" method of the same name. When
134 passed the name of a header, returns the value of the given
135 incoming header. When passed a name and a value, sets the value of
136 the header. Setting the header to "undef" will actually unset the
137 header (instead of setting its value to "undef"), removing it from
138 the table of headers returned from future calls to "headers_in()"
139 or "header_in()".
140 · headers_out()
142 This works much like the "Apache" method of the same name. In an
144 array context, it will return a %hash of response headers. In a
145 scalar context, it will return a reference to the case-insensitive
146 hash blessed into the "HTML::Mason::FakeTable" class. Changes made
147 to this hash will be made to the headers that will eventually be
148 passed to the "CGI" module's "header()" method.
149 · header_out()
151 This works much like the "Apache" method of the same name. When
153 passed the name of a header, returns the value of the given
154 outgoing header. When passed a name and a value, sets the value of
155 the header. Setting the header to "undef" will actually unset the
156 header (instead of setting its value to "undef"), removing it from
157 the table of headers that will be sent to the client.
158 The headers are eventually passed to the "CGI" module's "header()"
160 method.
161 · err_headers_out()
163 This works much like the "Apache" method of the same name. In an
165 array context, it will return a %hash of error response headers. In
166 a scalar context, it will return a reference to the case-
167 insensitive hash blessed into the "HTML::Mason::FakeTable" class.
168 Changes made to this hash will be made to the error headers that
169 will eventually be passed to the "CGI" module's "header()" method.
170 · err_header_out()
172 This works much like the "Apache" method of the same name. When
174 passed the name of a header, returns the value of the given
175 outgoing error header. When passed a name and a value, sets the
176 value of the error header. Setting the header to "undef" will
177 actually unset the header (instead of setting its value to
178 "undef"), removing it from the table of headers that will be sent
179 to the client.
180 The headers are eventually passed to the "CGI" module's "header()"
182 method.
183 One header currently gets special treatment - if you set a
185 "Location" header, you'll cause the "CGI" module's "redirect()"
186 method to be used instead of the "header()" method. This means
187 that in order to do a redirect, all you need to do is:
188 $r->err_header_out(Location => 'http://redirect.to/here');
190 You may be happier using the "$m->redirect" method, though, because
192 it hides most of the complexities of sending headers and getting
193 the status code right.
194 · content_type()
196 When passed an argument, sets the content type of the current
198 request to the value of the argument. Use this method instead of
199 setting a "Content-Type" header directly with "header_out()". Like
200 "header_out()", setting the content type to "undef" will remove any
201 content type set previously.
202 When called without arguments, returns the value set by a previous
204 call to "content_type()". The behavior when "content_type()"
205 hasn't already been set is undefined - currently it returns
206 "undef".
207 If no content type is set during the request, the default MIME type
209 "text/html" will be used.
210 · method()
212 Returns the request method used for the current request, e.g.,
214 "GET", "POST", etc.
215 · http_header()
217 This method returns the outgoing headers as a string, suitable for
219 sending to the client.
220 · send_http_header()
222 Sends the outgoing headers to the client.
224 · notes()
226 This works much like the "Apache" method of the same name. When
228 passed a $key argument, it returns the value of the note for that
229 key. When passed a $value argument, it stores that value under the
230 key. Keys are case-insensitive, and both the key and the value must
231 be strings. When called in a scalar context with no $key argument,
232 it returns a hash reference blessed into the
233 "HTML::Mason::FakeTable" class.
234 · pnotes()
236 Like "notes()", but takes any scalar as an value, and stores the
238 values in a case-sensitive hash.
239 · subprocess_env()
241 Works like the "Apache" method of the same name, but is simply
243 populated with the current values of the environment. Still, it's
244 useful, because values can be changed and then seen by later
245 components, but the environment itself remains unchanged. Like the
246 "Apache" method, it will reset all of its values to the current
247 environment again if it's called without a $key argument.
248 · params()
250 This method returns a hash containing the parameters sent by the
252 client. Multiple parameters of the same name are represented by
253 array references. If both POST and query string arguments were
254 submitted, these will be merged together.
255 Added $m methods
257 The $m object provided in components has all the functionality of the
258 regular "HTML::Mason::Request" object $m, and the following:
259 · cgi_object()
261 Returns the current "CGI" request object. This is handy for
263 processing cookies or perhaps even doing HTML generation (but is
264 that really what you want to do?). If you pass an argument to this
265 method, you can set the request object to the argument passed. Use
266 this with care, as it may affect components called after the
267 current one (they may check the content length of the request, for
268 example).
269 Note that the ApacheHandler class (for using Mason under mod_perl)
271 also provides a "cgi_object()" method that does the same thing as
272 this one. This makes it easier to write components that function
273 equally well under CGIHandler and ApacheHandler.
274 · cgi_request()
276 Returns the object that is used to emulate Apache's request object.
278 In other words, this is the object that $r is set to when you use
279 this class.
280 "HTML::Mason::FakeTable" Methods
282 This class emulates the behavior of the "Apache::Table" class, and is
283 used to store manage the tables of values for the following attributes
284 of <$r>:
285 headers_in
287 headers_out
288 err_headers_out
289 notes
290 subprocess_env
291 "HTML::Mason::FakeTable" is designed to behave exactly like
293 "Apache::Table", and differs in only one respect. When a given key has
294 multiple values in an "Apache::Table" object, one can fetch each of the
295 values for that key using Perl's "each" operator:
296 while (my ($k, $v) = each %{$r->headers_out}) {
298 push @cookies, $v if lc $k eq 'set-cookie';
299 }
300 If anyone knows how Apache::Table does this, let us know! In the
302 meantime, use "get()" or "do()" to get at all of the values for a given
303 key ("get()" is much more efficient, anyway).
304 Since the methods named for these attributes return an
306 "HTML::Mason::FakeTable" object hash in a scalar reference, it seemed
307 only fair to document its interface.
308 · new()
310 Returns a new "HTML::Mason::FakeTable" object. Any parameters
312 passed to "new()" will be added to the table as initial values.
313 · add()
315 Adds a new value to the table. If the value did not previously
317 exist under the given key, it will be created. Otherwise, it will
318 be added as a new value to the key.
319 · clear()
321 Clears the table of all values.
323 · do()
325 Pass a code reference to this method to have it iterate over all of
327 the key/value pairs in the table. Keys will multiple values will
328 trigger the execution of the code reference multiple times for each
329 value. The code reference should expect two arguments: a key and a
330 value. Iteration terminates when the code reference returns false,
331 to be sure to have it return a true value if you wan it to iterate
332 over every value in the table.
333 · get()
335 Gets the value stored for a given key in the table. If a key has
337 multiple values, all will be returned when "get()" is called in an
338 array context, and only the first value when it is called in a
339 scalar context.
340 · merge()
342 Merges a new value with an existing value by concatenating the new
344 value onto the existing. The result is a comma-separated list of
345 all of the values merged for a given key.
346 · set()
348 Takes key and value arguments and sets the value for that key.
350 Previous values for that key will be discarded. The value must be a
351 string, or "set()" will turn it into one. A value of "undef" will
352 have the same behavior as "unset()".
353 · unset()
355 Takes a single key argument and deletes that key from the table, so
357 that none of its values will be in the table any longer.
358perl v5.32.0 2020-07-28 HTML::Mason::CGIHandler(3)